Solved: How to hard reset Acer Stream S110: Turn off your phone, then press and hold the power unti...

Resetting your Acer Stream smartphone

You may have to perform a reset if your smartphone fails to respond when buttons are pressed or the screen is tapped.
Press the reset key under the battery cover. Remove the battery cover and use the battery cover tab to press the recessed reset key. Replace the battery cover when finished.
Note: Before performing a reset, ensure that your smartphone is not locked. Press any
key or tap the screen to see if the phone responds.

Acer Stream S110 Clean boot

A clean boot will restore your smartphone to the factory settings.
Warning! You should only perform a clean boot when all other options have failed to
restore your smartphone to an operational state.
Warning! This will erase all your personal information, any contacts stored on your
phone and any programs you installed.
If your phone is responding to screen input
Open Settings from the Application menu, then tap Privacy > Factory data reset; click Reset phone and then Erase everything to format your phone.
If your phone is not responding to screen input

Turn off your phone, then press and hold the power until you feel your smartphone vibrate and/or you see the Acer logo screen. Press and hold the Volume up and Volume down buttons. Use the Volume down button to select Clean boot: Yes. Press the camera button to confirm.